Surfactants are made use of in many organic chemistry syntheses.
This is the case, in particular, of emulsion polymerization processes, which offer the advantage of a high rate of reaction and a high degree of polymerization.
The emulsion polymerization, for example in water, generally uses a hydrophobic monomer, a surfactant forming micellar structures and an initiator. The reaction takes place inside the said structures and continues until the monomer is completely converted. Depending on the size of the polymer particles stabilized by the surfactant in the medium, a latex or a suspension is obtained.
Separation of the particles from the medium is made difficult by the presence of a surfactant, which tends to form highly stable emulsions or foams during the extraction step.
To overcome these drawbacks, cleavable surfactants have been proposed, inter alia, which are capable of decomposing into non-surfactant intermediates by an acid hydrolysis.
Among these surfactants, mention may be made of compounds having a labile structure of the 1,3-dioxane type, obtained by condensation of an aliphatic diol and a bromo aldehyde [WANG G. W. et al., JAOCS, Vol. 72, No. 1, pp. 83-87, 1995; JAOCS, Vol. 71, No. 7, pp. 727-730, 1994; JAOCS, Vol. 70, No. 7. pp. 731-732, 1993; J. Colloid and Interface Science, Vol. 173, pp. 49-54, 1995] or by acetalization of N-acetylglucosamine [KIDA T. et al., JAOCS, Vol. 72,-No. 7, pp. 773-780, 1995] or of glucono-1(5)-lactone [KIDA T. et al., JAOCS, Vol. 71, No. 7, pp. 705-710, 1994].
Mention may also be made of compounds having a labile structure of the 1,3-dioxolane type, such as cationic derivatives of alkyl 1,3-dioxolane (in the form of trimethylammonium bromides) [WILK K. A. et al., JAOCS, Vol. 71, No. 1, pp. 81-85, 1994], anionic derivatives containing one or two carboxylate groups [ONO D. et al., JAOCS, Vol. 72, No. 7, pp. 853-856, 1995] and nonionic derivatives obtained from L-galactono-1(4)-lactone.
The preparation of the surfactants which have just been mentioned usually requires many steps in which solvents and/or toxic reactants (for example dimethylformamide, benzene or acrolein) or starting materials that are not readily available (for example L-galactono-1(4)-lactone) are used.
It goes without saying that there is a great demand to have available novel cleavable surfactants which, in addition, are compatible with the skin and mucous membranes, are biodegradable and may be produced on an industrial scale from readily accessible starting materials.